Four main virotypes among extended-spectrum-β-lactamase-producing isolates of Escherichia coli O25b:H4-B2-ST131: bacterial, epidemiological, and clinical characteristics.

A total of 1,021 extended-spectrum-β-lactamase-producing Escherichia coli (ESBLEC) isolates obtained in 2006 during a Spanish national survey conducted in 44 hospitals were analyzed for the presence of the O25b:H4-B2-ST131 (sequence type 131) clonal group. Overall, 195 (19%) O25b-ST131 isolates were detected, with prevalence rates ranging from 0% to 52% per hospital. Molecular characterization of 130 representative O25b-ST131 isolates showed that 96 (74%) were positive for CTX-M-15, 15 (12%) for CTX-M-14, 9 (7%) for SHV-12, 6 (5%) for CTX-M-9, 5 (4%) for CTX-M-32, and 1 (0.7%) each for CTX-M-3 and the new ESBL enzyme CTX-M-103. The 130 O25b-ST131 isolates exhibited relatively high virulence scores (mean, 14.4 virulence genes). Although the virulence profiles of the O25b-ST131 isolates were fairly homogeneous, they could be classified into four main virotypes based on the presence or absence of four distinctive virulence genes: virotypes A (22%) (afa FM955459 positive, iroN negative, ibeA negative, sat positive or negative), B (31%) (afa FM955459 negative, iroN positive, ibeA negative, sat positive or negative), C (32%) (afa FM955459 negative, iroN negative, ibeA negative, sat positive), and D (13%) (afa FM955459 negative, iroN positive or negative, ibeA positive, sat positive or negative). The four virotypes were also identified in other countries, with virotype C being overrepresented internationally. Correspondingly, an analysis of XbaI macrorestriction profiles revealed four major clusters, which were largely virotype specific. Certain epidemiological and clinical features corresponded with the virotype. Statistically significant virotype-specific associations included, for virotype B, older age and a lower frequency of infection (versus colonization), for virotype C, a higher frequency of infection, and for virotype D, younger age and community-acquired infections. In isolates of the O25b:H4-B2-ST131 clonal group, these findings uniquely define four main virotypes, which are internationally distributed, correspond with pulsed-field gel electrophoresis (PFGE) profiles, and exhibit distinctive clinical-epidemiological associations.

Expression of PROKR1 and PROKR2 in Human Enteric Neural Precursor Cells and Identification of Sequence Variants Suggest a Role in HSCR

Background. The enteric nervous system (ENS) is entirely derived from neural crest and its normal development is regulated by specific molecular pathways. Failure in complete ENS formation results in aganglionic gut conditions such as Hirschsprung's disease (HSCR). Recently, PROKR1 expression has been demonstrated in mouse enteric neural crest derived cells and Prok-1 was shown to work coordinately with GDNF in the development of the ENS. Principal Findings. In the present report, ENS progenitors were isolated and characterized from the ganglionic gut from children diagnosed with and without HSCR, and the expression of prokineticin receptors was examined. Immunocytochemical analysis of neurosphere-forming cells demonstrated that both PROKR1 and PROKR2 were present in human enteric neural crest cells. In addition, we also performed a mutational analysis of PROKR1, PROKR2, PROK1 and PROK2 genes in a cohort of HSCR patients, evaluating them for the first time as susceptibility genes for the disease. Several missense variants were detected, most of them affecting highly conserved amino acid residues of the protein and located in functional domains of both receptors, which suggests a possible deleterious effect in their biological function. Conclusions. Our results suggest that not only PROKR1, but also PROKR2 might mediate a complementary signalling to the RET/GFRα1/GDNF pathway supporting proliferation/survival and differentiation of precursor cells during ENS development. These findings, together with the detection of sequence variants in PROKR1, PROK1 and PROKR2 genes associated to HSCR and, in some cases in combination with RET or GDNF mutations, provide the first evidence to consider them as susceptibility genes for HSCR.

FABP4 Dynamics in Obesity: Discrepancies in Adipose Tissue and Liver Expression Regarding Circulating Plasma Levels.

BACKGROUND FABP4 is predominantly expressed in adipose tissue, and its circulating levels are linked with obesity and a poor atherogenic profile. OBJECTIVE In patients with a wide BMI range, we analyze FABP4 expression in adipose and hepatic tissues in the settings of obesity and insulin resistance. Associations between FABP4 expression in adipose tissue and the FABP4 plasma level as well as the main adipogenic and lipolytic genes expressed in adipose tissue were also analyzed. METHODS The expression of several lipogenic, lipolytic, PPAR family and FABP family genes was analyzed by real time PCR. FABP4 protein expression in total adipose tissues and its fractions were determined by western blot. RESULTS In obesity FABP4 expression was down-regulated (at both mRNA and protein levels), with its levels mainly predicted by ATGL and inversely by the HOMA-IR index. The BMI appeared as the only determinant of the FABP4 variation in both adipose tissue depots. FABP4 plasma levels showed a significant progressive increase according to BMI but no association was detected between FABP4 circulating levels and SAT or VAT FABP4 gene expression. The gene expression of FABP1, FABP4 and FABP5 in hepatic tissue was significantly higher in tissue from the obese IR patients compared to the non-IR group. CONCLUSION The inverse pattern in FABP4 expression between adipose and hepatic tissue observed in morbid obese patients, regarding the IR context, suggests that both tissues may act in a balanced manner. These differences may help us to understand the discrepancies between circulating plasma levels and adipose tissue expression in obesity.

Application of Molecular Diagnostic Techniques for Viral Testing.

Nucleic acid amplification techniques are commonly used currently to diagnose viral diseases and manage patients with this kind of illnesses. These techniques have had a rapid but unconventional route of development during the last 30 years, with the discovery and introduction of several assays in clinical diagnosis. The increase in the number of commercially available methods has facilitated the use of this technology in the majority of laboratories worldwide. This technology has reduced the use of some other techniques such as viral culture based methods and serological assays in the clinical virology laboratory. Moreover, nucleic acid amplification techniques are now the methods of reference and also the most useful assays for the diagnosis in several diseases. The introduction of these techniques and their automation provides new opportunities for the clinical laboratory to affect patient care. The main objectives in performing nucleic acid tests in this field are to provide timely results useful for high-quality patient care at a reasonable cost, because rapid results are associated with improvements in patients care. The use of amplification techniques such as polymerase chain reaction, real-time polymerase chain reaction or nucleic acid sequence-based amplification for virus detection, genotyping and quantification have some advantages like high sensitivity and reproducibility, as well as a broad dynamic range. This review is an up-to-date of the main nucleic acid techniques and their clinical applications, and special challenges and opportunities that these techniques currently provide for the clinical virology laboratory.

Resuscitated sudden cardiac death caused by left main coronary artery compression by an aneurysm of the sinus of Valsalva.

A 49-year-old woman, without known cardiovascular risk factors. Hoarseness of voice caused by a paralysis of left vocal cord. She was admitted to hospital because of acute coronary syndrome, associated to resuscitated cardiac arrest (asystolia documented) without later neurology sequels. Physical examination was anodyne. Echocardiographic study demonstrated a compatible image with a large left sinus of Valsalva aneurysm (SVA) (Panel A) and mild aortic regurgitation. Cardiac catheterization confirmed the presence of left SVA (Panel B) that produced extrinsic compression of the left main coronary artery (Panels C and D). Repair surgery was made by means of closing the aneurysmal orifice with a patch of dacron. Intra-operatory echocardiographic control study found severe aortic regurgitation, so valvular replacement with 19 mm mechanical prosthesis and extension of the valve annulus with patch of dacron was performed, associated with bypass with safena vein graft to left coronary artery. SVA is a very infrequent cardiac anomaly, generally with silent clinical course until it ruptures. Myocardial ischaemia caused by coronary artery compression is unusual. We described the case of a patient diagnosed of left SVA, whose initial clinical manifestation was the appearance of resuscitated sudden cardiac death in the context of an acute coronary syndrome.

Mutation prevalence of cerebral cavernous malformation genes in Spanish patients.

OBJECTIVE To study the molecular genetic and clinical features of cerebral cavernous malformations (CCM) in a cohort of Spanish patients. METHODS We analyzed the CCM1, CCM2, and CCM3 genes by MLPA and direct sequencing of exons and intronic boundaries in 94 familial forms and 41 sporadic cases of CCM patients of Spanish extraction. When available, RNA studies were performed seeking for alternative or cryptic splicing. RESULTS A total of 26 pathogenic mutations, 22 of which predict truncated proteins, were identified in 29 familial forms and in three sporadic cases. The repertoire includes six novel non-sense and frameshift mutations in CCM1 and CCM3. We also found four missense mutations, one of them located at the third NPXY motif of CCM1 and another one that leads to cryptic splicing of CCM1 exon 6. We found four genomic deletions with the loss of the whole CCM2 gene in one patient and a partial loss of CCM1and CCM2 genes in three other patients. Four families had mutations in CCM3. The results include a high frequency of intronic variants, although most of them localize out of consensus splicing sequences. The main symptoms associated to clinical debut consisted of cerebral haemorrhage, migraines and epileptic seizures. The rare co-occurrence of CCM with Noonan and Chiari syndromes and delayed menarche is reported. CONCLUSIONS Analysis of CCM genes by sequencing and MLPA has detected mutations in almost 35% of a Spanish cohort (36% of familial cases and 10% of sporadic patients). The results include 13 new mutations of CCM genes and the main clinical symptoms that deserves consideration in molecular diagnosis and genetic counselling of cerebral cavernous malformations.

Impaired adipose tissue expandability and lipogenic capacities as ones of the main causes of metabolic disorders.

Obesity is considered a major health problem. However, mechanisms involved and its comorbidities are not elucidated. Recent theories concerning the causes of obesity have focused on a limit to the functional capacity of adipose tissue, comparing it with other vital organs. This assumption has been the central point of interest in our laboratory. We proposed that the failure of adipose tissue is initiated by the difficulty of this tissue to increase its cellularity due to excess in fat contribution, owing to genetic or environmental factors. Nevertheless, why the adipose tissue reduces its capacity to make new adipocytes via mesenchymal cells of the stroma has not yet been elucidated. Thus, we suggest that this tissue ceases fulfilling its main function, the storage of excess fat, thereby affecting some of the key factors involved in lipogenesis, some of which are reviewed in this paper (PPARγ, ROR1, FASN, SCD1, Rab18, BrCa1, ZAG, and FABP4). On the other hand, mechanisms involved in adipose tissue expandability are also impaired, predominating hypertrophy via an increase in apoptosis and a decrease in adipogenesis and angiogenesis. However, adipose tissue failure is only part of this great orchestra, only a chapter of this nightmare.